Alarm device for rotating shafts



June 19, 1962 w. H. BOOKWALTER 3,039,426

ALARM DEVICE FOR ROTATING SHAFTS Filed Dec. 23, 1960 I N VEN TOR. 4016;. WW Em m w m E WW United States Wash.

Filed Dec. 23, 1960, Ser. No. 78,140 3 Claims. (Cl. 11660) This invention relates to a novel and useful alarm device for rotating shafts, and more particularly to an alarm device specifically adapted to be mounted upon a rotating axle and to provide an audible alarm upon rotation of the axle.

It is the main object of this invention to provide an alarm device which will be readily adapt-able for use in conjunction with substantially all rotating shafts and which will be capable of rendering a loud audible signal upon rotation of the shaft to which it is secured.

A further object of this invention, in accordance with the preceding object, is to provide an alarm device which will be capable of rendering a loud audible signal upon rotation of the shaft to which it is secured in either direction.

A still further object of this invention, in accordance with the preceding objects, is to provide an alarm device of the bell-type having a gong and clapper means with the device also including actuating means for positively actuating the clapper means for engagement with the gong.

Still another object of this invention is to provide an alarm device having clapper means which is mounted relatively stationary and against rotation with the shaft to which the alarm device is secured whereby the clapper means will be uneffected by centrifugal force even if the shaft is rotated at high speeds.

Yet another object of this invention, in accordance with the immediately preceding object, is to provide an alarm device for rotating shafts which will not depend in any way upon centrifugal force effected by any portion of the rotating shaft.

A final object to be specifically enumerated herein is to provide an alarm device which will conform to conventional forms of manufacture, be of simple cons-truction and easy to install so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the alarm device shown mounted upon the rotating shaft of a wheel;

FIGURE 2 is a rear view on an enlarged scale of the device illustrated in FIGURE 1;

FIGURE 3 is a view similar to that of FIGURE 2 but showing the clapper means of the alarm device in an alternate position of operation;

FIGURE 4 is a longitudinal vertical sectional view taken along the section line 44 of FIGURE 2 with parts broken away and shown in section;

FIGURE 5 is a horizontal sectional view taken substantially upon the plane indicated by section line 5-5 of FIGURE 2;

FIGURE 6 is a fragmentary horizontal sectional view taken along the section line 6-6 of FIGURE 2.

Referring now more specifically to the drawings the numeral 10 generally designates one wheel of a wheeled vehicle (not shown) adjacent to which the alarm device of the instant invention is mounted. The alarm device atent G 3,039,426 Patented June 19, 1962 "ice is generally designated by the reference numeral 12 and is mounted on the axle 14 of the vehicle on which the wheel 10 is secured.

The alarm device 12 includes a gong 16 which is mounted on the free end of the shaft 14 by means of a pair of lock nuts 18 and 20. A cam member or element 22 is fixedly mounted on the shaft 14 in any convenient manner for rotation therewith and clapper means generally designated by the reference numeral 24 and in the form of a support member 26 is rotatably journaled on the shaft 14 between the nut 20 and the cam element 22. The support member 26 is eccentrically weighted so that it will remain substantially stationary while the shaft 14 rotates. The support member has a pair of clapper arms generally designated by the reference numerals 28 and 30 pivotally mounted thereon by means of pivot pins 32 and 34 respectively. The clapper arms 28 and 30 have clapper elements 36 and 38 respectively which are in the form of spherical enlargements formed on the free end of the arms 28 and 30. Each of the arms 28 and 30 includes an angulated leg portion 40 which projects inwardly from the pivot pins toward the axle shaft 14. A lever arm 42 has one end pivotally secured to the support member 26 between the pivoted ends of the arms 28 and 30 by means of pivot pin 44. The free end of the lever 42 is provided with a transverse connecting member 46 which is generally U-shaped in horizontal cross section and includes a pair of legs 48 interconnected by means of a bight portion 50.

The arms 28 and 30 are free to pivot about the pivot pins 32 and 34 with the free ends thereof on which the clapper elements 36 and 38 are disposed movable toward and away from the outer marginal portion of the gong 16. However, each of the arms 28 and 30 includes an anchor pin 52 and a leaf spring 54 is secured between each of the pivot pins 32 and 34 and the corresponding anchor pin 52 to resiliently urge the arms 28 and 30 to a rest position with the clapper elements 36 and 38 thereof spaced slightly from the outer marginal portion of the gong 16.

The connecting member 46 establishes a lost motion connection between the lever 42 and each of the legs 40 of the arms 26 and 30. The connecting member 46 is capable of urging the free end of the legs 40 toward the radius of the axis of rotation of the shaft 14 along which the lever 42 is normally disposed by means of the springs 54. Thus, the springs 54 not only serve to properly position the clapper elements 36 and 38 but also to normally resiliently urge the lever 42 to a position coinciding with the radius of the axis of rotation of the shaft 14.

In operation, upon rotation of the shaft 14 in a clockwire direction when viewed in FIGURE 2 of the drawings, the lobe 56 of the cam element 22 will engage the free end of the lever 42 whereupon the connecting member 46 will urge the free end of the leg of the arm 30 toward the leg of the arm 28, as illustrated in FIGURE 3 of the drawings. When the lobe 56 is rotated past the position illustrated in FIGURE 3 of the drawings, the free end of the lever 42 will be freed from engagement with the cam element 22 and the spring 54 on the leg 30 will urge that leg to a normal rest position which may be viewed in FIGURE 2 of the drawings. However, the inertia of the arm 30' will carry it past its rest position and its clapper element 38 into engagement with the gong 16 rendering an audible signal. Upon rotation of the shaft 14 in a clockwise direction as viewed in FIGURE 2 of the drawings, the clapper arm 28 will remain inactive except to assist in returning the lever 42 to its rest position on a radius of the axis of rotation of the shaft 14.

However, upon rotation of the shaft 14 in a counterclockwise direction as viewed in FIGURE 2 of the drawings, the clapper arm 30 will be maintained inactive and the clapper arm 28 will be moved away from the gong 16 upon engagement of the lobe 58 with the free end of the lever 42.. Thus, it will be noted that the alarm device 12 is capable of rendering an audible signal upon rotation of the shaft 14 in either direction and also that the alarm device 12 in no way depends upon centrifugal force or could be efiected "by any centrifugal force caused by the rotation of the shaft 14 at a high speed.

Although it is not deemed to be necessary tospecifically show the manner in which the alarm device 12 could be mounted upon a rotating wheel journaled on a stationary shaft, it is to be understood that in this case the cam element 22 would be journaled on the stationary shaft and secured to the wheel for rotation therewith. The support member could then be fixed to the shaft in order to assure that it will remain stationary. Additionally, the cam element 22 could be fixed on the stationary shaft and the support member and gong could be fixed on the wheel rotated on the shaft for rotation with the wheel. It will be noted that the support member is substantially symmetrical and therefore that centrifugal force would not elfect its operation. Further, inasmuch as the distance between the clapper elements 36 and 38 cannot be increased beyond that illustrated in FIGURE 2 of the d a ings because of the connecting member 46, even if centrifugal force were applied the operation of the alarm device 12 Would still be dependable.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a horizontally disposed rotating shaft, an alarm device comprising a gong concentrically on said shaft for rotation therewith, an eccentrically weighted support member journaled on said shaft and disposed within said gong, a pair of clapper arms, means pivotally mounting corresponding ends of said arms to said support member for rotation about axes generally paralleling the axis of rotation of said shaft, cam means mounted on said shaft for rotation therewith, means resiliently urging said clapper arms to rest positions with the free ends thereof slightly spaced from adjacent portions of the outer periphery of said gong, said clapper arms including legs extending outwardly from said corresponding ends generally paralleling each other, a connecting lever having one end pivotally secured to said support member for rotation about an axis paralleling the axes of rotation of said arms, disposed between the medial planes of said arms and with said lever generally paralleling and extending bet-ween said legs, a connecting member car ried bythe free end of said lever and including means providing lost motion connection between said lever and said legs limiting movement of the free end or" said lever from said legs, said cam means being engageable with the free end of said lever for oscillating the latter and selectively moving the free end of said lever away from the free ends of said arms where each of said clapper arms may, depending upon the direction of rotation of said shaft, have its *free end moved successively away from said gong and then released whereby when said arm is released said resilient means for urging said arm toward said rest position and the inertia of said arm will carry it past the rest position into engagement with said gong.

2. The combination of claim 1 wherein said connecting member comprises a shallow U-shaped member including a pair of legs generally paralleling the axes of rotation of said arms interconnected by means of a bight portion extending transversely of said lever and secured to the lever, said connecting member legs comprising abutments engageable with the sides of said clapper arm legs remote from said lever.

3. The combination of claim 1 wherein said resilient means for urging said clapper arms to said rest positions urge said lever arm to a position lying on a radius of the axis of rotation of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS Re. 3,234 Taylor Dec. 15, 1868 2,802,441 Epstein Aug. 13, 1957 

